1. Field of the Invention
The present invention relates to an image stabilization mechanism and an image pickup apparatus and, in particular, to technology that produces a compact image stabilization mechanism capable of moving in a plane in two directions perpendicular to each other without rolling thereof and with a small number of components thereof.
2. Description of the Related Art
Some image pickup apparatuses (e.g., video cameras, still image cameras, or camera units incorporated in portable electronic devices, such as cell phones) include an image stabilization mechanism. The image stabilization mechanism compensates for image blurring caused by camera shake occurring when a shutter is released.
In general, an image stabilization mechanism employs one of the following three methods: a lens driving method, an image sensor driving method, and an electronic correction method. In a lens driving method, if an image is deviated in a direction perpendicular to a light axis due to the movement of the light axis caused by camera shake, a lens (or a lens group) of a lens system is temporarily moved in the direction perpendicular to the light axis so as to change the light path through the lens (hereinafter referred to as a “compensation lens”). In this way, the subject image is formed in an imaging plane at its proper position. In an image sensor driving method, an image sensor is moved so that the image forming position deviated from its proper position due to camera shake is moved back to the original position. In an electronic correction method, the image forming position deviated from its proper position due to camera shake is corrected through an electronic operation.
In the lens driving method and the image sensor driving method, a compensation lens or an image sensor needs to be moved in two directions perpendicular to the light axis. Accordingly, for example, an image stabilization mechanism described in Japanese Unexamined Patent Application Publication No. 3-188430 includes a stationary base member (a second holding frame 119) fixed to a camera body. The stationary base member supports a movable base (a first holding frame 16) in a movable manner in a first direction (a yaw direction) perpendicular to a light axis. The stationary base member further supports a first driving unit (a combination of a yaw coil 121, a yaw magnet 122, and a yaw yoke) for moving the movable base in the first direction. The movable base supports a movable frame (a lens holding frame 13) in a movable manner in a second direction (a pitch direction) perpendicular to the light axis and the first direction and a second driving unit (a combination of a pitch coil 18, a pitch magnet 19, and a pitch yoke 110) for moving the movable base in the second direction. The movable frame supports a compensation lens.